The purpose of this research project is to clarify the organ specific transports of drugs from the view points of organ, cell, molecular and gene levels and to develop novel method for regulation of pharmacokinetics and pharmacodynamics of drugs. The following results were obtained by two years term of this research project consisted of 14 investigators :1.Several evidences were obtained for molecular and biological characteristics of transporters involved in the buccal and intestinal absorption and secretion, renal secretion and reabsorption, hepatic uptake and biliary secretion and in the brain influx and efflux transports. Cloning of transporters of PepT1, PepT2, MCT1, cMOAT,OAT-K1 and OCT2, their transport functions and tissue distribution were clarified. It was also clarified that P-glycoprotein functions as the transport barrier for lipophilic xenobiotics in the intestine and at the blood-brain barrier (BBB). Peptides were confirmed to be taken up by adsorptive-mediated endocytos
… Moreis at the BBB to be delivered into the brain. 2.Improvement of absorption for drugs was achieved by glycosylation, endocytosis across Peyer's patches, iontophoretic method and by absorption enhancers to open tight junction. 3.Uptake of fractionated heparin by hepatocytes and Kupffer cells was clarified to be regulated by the scavenger receptor-mediated and plasma proteins-mediated mechanisms. Liver-specific delivery of drugs, proteins and gene was achieved by using galactosylated technology. Reactive oxygen species, such as superoxide and nitric oxide (NO), were clarified to play critical roles in the pathogenesis of various diseases. To overcome the oxidative stress, synthesized site-directed SOD derivatives were succeeded to deliver the targeting cells. An attractive approach for the antibody-based therapy of solid tumors was proposed and evaluated successfully by use of "vascular targeting" antibody to recognize tumor endothelial cells. 4.Using alpha 1-adrenoreceptor as a model, cloning of the receptors and detection of the tissue localization of the receptor protein were succeeded. It was indicated that uridine receptor plays some role not only in brain but also in peripheral tissues. Pharmacokinetic and pharmacodynamic behaviors for the transport in the brain, receptor binding and analgesic action were analyzed after peptazocine administration in rats.2.グリコシド化、粘膜接着性、パイエル板のエンドサイトーシス活性、イオントフォレ-シスの利用あるいは細胞間隙拡大物質による低・高分子薬物の吸収促進機能を解明した。3.分画へパリンのスカベンジャーレセプター及び血漿蛋白質が介在する肝移行制御、ガラクトース修飾蛋白質の肝特異的分布性の調節、活性酸素やNOラジカルが病態制御因子として重要な役割を演じることをつきとめ、部位指向性SODを標的病態臓器に集積させることに成功した。また、腫瘍臓器血管内皮細胞に対するモノクロナール抗体を利用した斬新な癌ミサイル療法の道を開いた。4.α_1受容体をモデル系として、ヒト薬物受容体のクローニングとその細胞内情報伝達機構を解析した。また、脳内および抹消組織には、それぞれN^3-フェナシルウリジンおよびウリジンと強い親和性を有するレセプターの存在を示唆する新規な結果を得た。ペンタゾシンをラットに投与後の血漿中・脳内濃度と鎮痛効果の時間推移を薬物動態学的に解析し、神経活動の制御機構を解明する方法を開発した。以上の成果により、本総合研究は初期の目的をほぼ達成することができた。 Less